Crude coal tar dermatological compositions



Patented July 1, 1952 CRUDE COAL TAR DERMATOLOGICAL COMPOSITIONS Irving B. Wershaw, New York, N. Y., assignor'to Dome Chemicals, Inc., New York, N. Y., a corporation of New York NoDrawing. Application May 24, 1950, Serial No. 164,033

9 Claims.

This invention relates to a crude coal tar composition suitable for dermatological uses.

Crude coal tar has been used extensively in the dermatological field (New England Journal of Medicine 228: 384-386, March 25, 1943; article by Frank C. Combes, MD. in Industrial Medicine, July 1944-). As heretofore used, notwithstanding'the relatively small proportion of crude coal tar present in the composition applied to the skin, usually of the order of 2% by weight, the composition had a black'messy appearance. Further, it stained articles of apparel, linens, bedclothing, etc. with which it came in contact, which stains were difiicult to remove. These factors, particularly its messy appearance, have tended to discourage use of crude" coal tar compositions for dermatological uses even-though beneficial. Much research and development work has been devoted to this problem. To the best of my knowledge and belief, however, all attempts made prior to my invention to mask or change the color of the crude coal tar without detrimentally affecting its pharmacologic action have proved unsuccessful.

It is an object of this invention to provide a crude coal tar composition of cosmetically elegant ap earance and'in which the pharm'acologic action of the coal tar is not detrimentally affected.

Other objects and advantages of this invention will be apparent from the "following detailed description thereof.

By crude'coal tar as used herein is meant the crude coal tar product obtained as a by-product in the distillation of coal (anthracite or bituminous) to produce combustible gas, which distillation may be carried out either at relatively high temperatures, for example, in by-product coke ovens or retorts, or at lower temperatures as in the so-called low temperature coal distillation procedures. The termcrud'e coal tar as used herein does not include 'distillates, oil fractions or pitch residues obtained from crude coal tar. It does mean the heterogeneous mixtureiobtained as a by-product in the manufacture of combustible gas as hereinabove described. In the case of tars separated say in the 'collectorfimains .or other parts of the by-product'recovery equipment in which the tar is sprayed'with an aqueous medium, the crude coal tar is. dehydrated sothat it contains little or no water. commerce, which is a dehydrated coal tar and contains substantially all of the light oils, middle oils, heavy oils, anthracene oils and pitch, is suitable. This tar is black in color and when mixed Crude coal tar of with'starch, petrolatum or other carrier, asheretofore produced, has .a disagreeable appearance; the color "varies from a dirty grey or brown to an objectionable black.

I have made the surprising and commercially important discovery that by mixing with each part by weight of crude coal tar'from 10 to 40 parts by'weight of a wetting'agent which has the property of dispersing the coal tar .and from 1 to 15 parts "by weight of'finelydivided titanium dioxide, a cosmetically elegant crude coal tar composition results. inwhich none of the pharmacological properties of the coal tar 'aredeleteriously afiected. Furthermore, the resulting composition, surprisingly does not form objectionable stains on the skin, linens, bedclothes or other surfaces with which it may come in contact. The composition can readily be removed from such surfaces by simply'washingv them with water, if desired, with soap and Water.

The composition hereinabove described may be packaged for storage orshipment in any suitable size package. When it is desired to apply same the composition is added to. asuitable'absorption, washable, dispersible .carrier, such as a solid carrier consisting of a mixture of oils, waxes,

emulsifiers, wetting agents and water, or a liquid carrier such as the mineral oils, e. g., liquid petrolatum. Examples of such solid carriers are the creams sold under the trade names Omnia Creme, Alcolan and Neobase. These-carriers function to absorb the serous exudates -and to spread the crude coal tar composition. The composition is added to the carrier in proportions to produce a mixturecontaining from about 1% to 5%, preferably 2% to 3% of crude coal tar based on the weight .oflthe mixture.

Preferably, however, I mix the constituents in proportions to produce a composition which is ready for application. Thus per :part of .crude tar I add from 10 -to-40, preferablyZO to 30,.parts by weight of wetting agent, from 1 to 15, preferably 3 to 10, parts by weight of titanium dioxide from 10 to 40, preferably, 15 to 20, parts by weight of absorbent filler for the serous exudates, such-asstarch, etc.,-and from 1 to 15,-.preferably 3=to 10, parts by weight ofan astringent, such as zinc oxide. 'This mixtureis added-tea carrier which may be a solid carrier asd'escribedabove, or liquid carrier, 1e. -g.,:-mineral oiltggprocluce amixturecontaining 2% cru'decoaltar,

As the wetting agent any agent capable of emulsifying the crude coal tar may be used.-

Among such agents may be mentioned the polyalkylene derivatives of partial esters of hexitol anhydride and long chain fatty acids, such as polyoxyalkylene sorbitan monolaurate sold under the trade name Tween 20, the corresponding palmitates (Tween 40), stearates (Tween 60). polyoxyalkylene ether of sorbitan monooleate, alkyl aryl sulfonates (Nacconols) sodium salts of sulfated higher fatty alcohols (Gardinol, Duponal), etc. The preferred wetting agent is Tween 20.

The state of subdivision of the titanium dioxide is not critical. A titanium dioxide in finely divided form such as that used for pigment purposes may be employed.

In making the composition of this invention the crude coil tar is first mixed with the wetting agent until a homogeneous dispersion results. Usually mixing for about 30 minutes suffices to produce a satisfactory dispersion. The titanium dioxide is then added and the mixing continued. Surprisingly, I have found the finely divided titanium dioxide becomes homogeneously distributed throughout the mixture resulting in a composition having a cosmetically elegant appearance and this without detrimentally affecting the pharmacological properties of the crude coal tar. Furthermore, the resultant mixture when applied can readily be washed oil the skin, linens, bedclothing etc. with water or water and soap without leaving noticeable stains. This is indeed surprising in view of the complete immiscibility of crude coal tar with water.

The following example is illustrative of a composition embodying my invention. It will be understood the invention is not limited to this example. In this example parts are by weight:

Parts Crude coal tar 300 Tween 20 3000 Titanium dioxide 150 Zinc oxide 850 Corn starch 4000 Liquid or solid absorbent base as hereinabove described 6400 Since certain changes may be made in the above composition of matter and different embodiments of the invention could be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from to 40 parts by weight of a wetting agent and from 1 to parts by weight of finely divided titanium dioxide.

2. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from 10 to 40 parts by weight of a polyalkylene derivative of a partial ester of hexitol anhydride and from 1 to 15 parts by weight of finely divided titanium dioxide.

3. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from 10 to 40 parts by weight of a. polyalkylene derivative of a long chain fatty acid and from 1 to 15 parts by weight of finely divided titanium dioxide.

4. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from 10 to 40 parts by weight of a polyoxyalkylene sorbitan monolaurate and from 1 to 15 parts by weight of finely divided titanium dioxide.

5. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from 20 to 30 parts by weight of a polyoxyalkylene sorbitan monolaurate and from 3 to 10 parts by weight of finely divided titanium dioxide.

6. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from 10 to 10 parts by weight of a wetting agent, from 1 to 15 parts by weight of finely divided titanium dioxide, from 10 to 40 parts by weight of absorbent filler, from 1 to 15 parts by weight of an astringent, and a carrier in amount sufiicient to produce a mixture containing approximately 1% to 5% by weight of crude coal tar.

'7. A crude coal tar composition suitable for dermatological uses containing per part of crude coal tar from 20 to 30 parts by weight of a polyalkylene derivative of a compound from the group consisting of the partial esters of hexitol anhydride and long chain fatty acids, from 3 to 10 parts by weight of finely divided titanium dioxide, from 15 to 30 parts by weight of starch, from 3 to 10 parts by weight of zinc oxide and sufficient absorbent carrier to produce a mixture containing approximately 1% to 5% by weight of crude coal tar.

8. A crude coal tar composition suitable for dermatological uses containing per part of crude coai tar from 20 to 30 parts by weight of polyoxyalkylene sorbitan monolaurate, from 3 to 10 parts by weight of finely divided titanium dioxide, from 15 to 30 parts by weight of starch, from 3 to 10 parts by weight of zinc oxide, and suflicient absorbent carrier to produce a mixture containing approximately 1% to 5% by weight of crude coal tar.

9. A crude coal tar composition suitable for dermatological uses containing about 300 parts by weight of crude coal tar, about 3000 parts by weight of polyoxyalkylene sorbitan monolaurate, about 450 parts by weight of finely divided titanium dioxide, about 850 parts by weight of zinc oxide, about 4000 parts by weight of starch, and about 6400 parts by weight of absorbent carrier.

IRVING B. WERSHAW.

REFERENCES CITED The following references are of record in the file of this patent:

Meredith et al J. Am. Pharm. Assoc, 18 pages, 607 to 608 (1929).

Huston, Canadian Pharmaceutical Journal, November 15, 1948, pages 999 to 1000.

Gliokman, Soap Sanitary Chemicals, May 1948, page 81.

Drug and Cosmetic Emulsions Pamphlet, Atlas Powder Company, Wilmington, Delaware, Copyright 1946, pages 36 to 38, 43.

Bennett, The Chemical Formulary, volume VIII, 1948, page 102.

Osol et al., The Dispensatory of U. S., 24th edition, 1947, J. P. Lippincott Company, page 1228. 

1. A CRUDE COAL TAR COMPOSITION SUITABLE FOR DERMATOLOGICAL USES CONTAINING PER PART OF CRUDE COAL TAR FROM 10 TO 40 PARTS BY WEIGHT OF A WETTING AGENT AND FROM 1 TO 15 PARTS BY WEIGHT OF FINELY DIVIDED TITANIUM DIOXIDE. 